Rapid Prototype Trends

3D solid model software has come a long way.  It  makes complex finite element analysis an integrated feature so that new designs can be explored in hours, rather than days or weeks of building prototype parts and making changes.  New product development costs have been falling consistently since the advent of this technology.

The logical extension of 3D solid modeling software is 3D rapid prototyping.  This technology has also gone through significant changes over the last twenty years to reduce the cost and make it available to a wide audience.  Development of file format conventions have made the link between 3D solid modeling and 3D printing very straightforward.

In its early days, 3D printing started out as stereolithography.   This term was coined for the two laser beams that were used to cure liquid polymer in a large tank.  Precision steering and focusing of laser beams has been around for a while from the laser printer world.  Adapting the laser printer technology resulted in tremendous precision with part accuracy of .001″ in any dimension being easily achieved.  This made evaluating complex fit and function very easy for manufacturers.  At its inception, stereolithograyphy machines were $250,000.  The high price tag made stereolithography the domain of Fortune 500 companies. But for high volume, complex parts like intake manifolds for automotive engines, stereolithography was, and still is, a great way to save money when a new part design is required.

Heat curing a liquid polymer gave way to heating a low melt point polymer to a liquid and dispensing it in small beads as a lower cost solution for making complex shapes.  To the point where there are a wide variety of solid model printers in a desktop package that are priced under $20,000 with really sophisticated features like multicolor part generation, and new low end machines coming in from China at $1500.

Experimentation with different chemistries has created a wide range of options with regard to material strength and imparting unique properties to the parts.  One variation is ABS plastic that is available with glass fill.  This produces much higher strength parts than the polymers.  Another whole branch of 3D printing is dedicated to making metal parts that are too complex or expensive for conventional machining.  Amazingly, the 3D-based solutions are resulting in much lower costs.

The implications are transformational for new product  development.  First, the combination of 3D solid model software and 3D printing technology taken together represent an order of magnitude reduction in the cost of developing new products.  The technology make more information available leading to, hopefully, better design.  This also means that the amortization cost of the development activity is also greatly reduced.  Leading to better goods at lower prices.

The second transformation is that lower development costs mean that the technology can be applied to lower price products.  Previously, these technologies were only cost effective in automotive and medical instrument design applications.  Now, the potential exists to dramatically improve products at lower price and volume levels.  Sneakers, for example, have been impacted by this technology leading to a wide range of new products incorporating a variety of new ideas.

And the transformation is just beginning.  And all of it mechatronics driven.

Prototyping and Simulation

Maybe my insight is not new.  But I thought it was interesting nonetheless.

I have been working on a project in the solar energy arena.  My company is developing a two axis tracking system that will improve the energy harvest of flat roof and residential solar installations.  Its going really well.  A real mechatronic challenge.  The magic is in creating an electromechanical solution that moves a single solar panel cost effectively.  Not an easy project.

We modeled the initial solution and found some limitations in the range of motion that would have negative effect on the energy harvest.  Its easy to get the solar panel to rotate 45 degrees to the east from a flat storage position.  But that isn’t always enough to maximize the amount of solar energy converted to electricity.  And when the elevation angle is combined with the rotation of the azimuth, there were significant limits to the motion, and therefore limits the amount of energy from the solar panels.  So we started working on an improved solution.

This, by the way, is the great thing about software simulation.  You can study something without making any hardware.

And this lead me to think about the nature of solid model and finite element analysis software.  I think there may be a mis-impression about the nature of these products.  The goal of solid modeling is not to eliminate the prototyping process, the goal is to make prototyping faster and less expensive.  Which goes hand in hand with the explosion in rapid prototyping technology.  More on that later.

Maybe its a poor analogy, but I can’t help recalling Thomas Edison’s search for the improved electric light.  And by the way, Edison didn’t patent the electric light.  He improved it after purchasing a Canadian patent from Dr. Henry Woodward and Matthew Evans.  The electric light was first demonstrated by Sir Humphry Davy in 1809, but it was a platinum filament powered by a huge array of batteries.  And the race was on for the balance of the 1800′s with people all over the world trying to come up with a solution that would make electric light practical.

Anyway, Edison is said to have conducted ten thousand experiments with the goal of creating a light source that would have sufficient life expectancy to be commercially viable.  Solid modeling would not have helped Edison since the work was primarily based on material science.    But modeling software has become so widespread and so powerful, that it is very widely used in product development.

The key thing to remeber is that software is a tool.  It has its uses, and it has its flaws.  We’ve found several flaws along the way.  But it allows us to work with the design and understand the system’s physical properties before we cut metal.  This saves huge amounts of time and money.  But it does not replace the fabrication step.  Even in a system as simple as the one I am working with, it is clearly necessary to build hardware and test performance.  There are too many areas that software models are not sufficiently detailed to be able to analyze reliably.

Nothing replaces hardware and testing.  Not yet.

Siemens PLM Mechatronics Software Derived From Video Games

Siemens PLM Software announced a new integrated machine design solution aimed at creating value for companies that develop and market machine tools and production machines. Mechatronics Concept Designer™ represents a paradigm shift for the industry with a new systems engineering approach to machine design that captures “voice of the user ” input, manages early requirements and facilitates the simultaneous definition and simulation of the complex mechanical, electrical and automation software found in today’s increasingly complex machine tools. With an easy-to-use, interactive simulation capability based on groundbreaking “gaming” technology, Mechatronics Concept Designer can help significantly reduce development time and improve product quality for the global machine design industry.

Siemens PLM Software’s Mechatronics Concept Designer solution enables entire development teams to collaborate more effectively from the beginning to the end of the machine design process, thereby allowing them to catch and easily correct issues early, before they become costly manufacturing or customer related problems.

An Integrated End-to-End Systems Engineering Approach

The development process in the machine tool industry requires experts from several different disciplines, including mechanical, electrical, and software design, to develop a complex machine to the specific requirements of each individual customer. Traditional software tools don’t take requirements into account, and the lack of a “common language” has made it difficult for these disciplines to integrate with each other until the end of the design process when changes are more costly, both in time and money. This fragmented set of design applications combined with the complexity of the machines, has made it virtually impossible to simulate and evaluate various design concepts to support rapid and effective product development decision making.

Siemens PLM Software’s Mechatronics Concept Designer enables mechanical, electrical, and software/automation disciplines to work in parallel. It includes all the powerful mechanical design features of NX while enabling the user to develop a list of sensors and actuators which can be easily selected and positioned, laying the foundation for the electrical engineers to create the layout plan. And more efficient software development is supported through the ability to make the machine’s sequence of operations available in a standard format common in the machinery industry.

Working in conjunction with Teamcenter, the world’s most widely used PLM system, Mechatronics Concept Designer delivers an end-to-end machine design solution with an integrated systems engineering approach. At the beginning of the development cycle, designers can use the Teamcenter requirements management and systems engineering capabilities to build a functional model that ensures customer requirements are incorporated into the design.

Video Game Technology Enables Groundbreaking Simulation

Mechatronics Concept Designer also includes a state-of-the-art modeling and simulation capability based on NVIDIA® PhysX® technology. This physics engine, developed with the PhysX SDK from NVIDIA, is similar to the software technology used in many of today’s modern video games. This groundbreaking approach to simulation makes it easy to quickly create and interactively validate alternative design concepts. In addition, the user is able to interact with the digital machine model while the simulation is running, providing the ability to test the effects of different inputs in real time. The ability to model real-world physical behavior in the virtual world, based on simplified mathematical models, enables early concept verification that helps detect and correct errors when they are least expensive to resolve.

Siemens PLM Software at IMTS

Mechatronics Concept Designer is being demonstrated in booth number E-4040 at IMTS. Attendees at IMTS also have the opportunity to observe several other technology solutions from Siemens designed to maximize manufacturing productivity including the Tecnomatix Virtual Machine solution mentioned above.

www.siemens.com

Applied Time and Motion

From the control system perspective, I find it interesting that we continue to model most industrial applications of motors with trapezoidal “time displacement” curves and PID (proprotional integral and derivative) tuning algortihms.  It seems that we should have better definitions for things after all the time and effort that goes into it.

It is important to see that the graphical representation of motion in “time displacement” plot is also a very literal representation of the mechanical aspect of motion.  The area under the curve is the mechanical work done by the system.

The acceleration leg of the trapezoid is the energy needed to bring the load from rest to a constant speed.  The acceleration profile is expressed simply as a scalar changing velocity that is increasing in value until the desired speed is reached.  The first derivative of velocity is acceleration, or the rate of increase of velocity over the unit change in time.

What might be of interest here is that the acceleration changes from a positive value to zero when the desired speed is reached.  Then acceleration is zero, because the system command will be for a constant speed with no acceleration.  And in PID type controls, the transition from positive acceleration to a zero acceleration invariably causes velocity overshoot.

Since everything can be mapped with respect to time, isn’t it more straightforward to consider the inflection points along the way and change the control methodology according to what is going on in the real world?

So coming up to the transition from accelerating to not accelerating, we know that the first derivative value is decreasing to zero.  Maybe our control strategy should be to switch from the velocity loop control and switch to the torque loop so we can decrease the current going to the motor.  This will soften the transition point and minimize overshoot without the use of PID control.

Torque control during fixed position control also has some intuitive benefits.  Any disturbance in position is countered by an opposing torque, or current control through the servoamplifier, to restore position.  This behavior can be embedded in the amplifier and does not require intervention from the controller, minimizing control system loading.

PID control, while enormously successful over the years, is a sort of averaging solution. We will apply gain values across a wide range of motion conditions in hope that they will work satisfactorily for all states over the time of the move .   But if we consider other possibilities, other strategies for control become possible.

This has been the goal of “adaptive gain” solutions which exist today and have evolved over the years as control technology has become cheaper and more powerful and the industry has acknowledged the weaknesses of PID control. By paying attention to the “inflection points” along the trajectory fo the motion, different control strategies are made possible that are simple, reliable and in some cases, more robust than what is possible with conventional control.

Giant Robotic Arm Simulates Driving a Ferrari

The hot-pink industrial arm whips you around while you sit in the driver’s seat


This image shows the robotic arm Ferrari simulator without a steering wheel attached. The simulator includes a force-feedback steering wheel and pedals.

Paolo Robuffo Giordano and colleagues at the Max Planck Institute for Biological Cybernetics in Tübingen, Germany, must really enjoy their jobs. Their CyberMotion Simulator is intended to realistically replicate the experience of driving a Ferrari without actually having to buy one.

Players sit in a cabin on a robot arm about 7 feet off the ground and drive a Ferrari F2007 car around a projected track. The robot arm, a type usually found in amusement parks, whips the driver around to simulate the Ferrari’s motion, according to IEEE Spectrum. You can hear the robot whine as the driver tries to turn at high speed.

The researchers wanted to use a robotic arm as a motion simulator with the goal of understanding how humans experience the sensation of motion. They figured an F1 racing game would be a good way to do it, IEEE Spectrum reports.They presented a paper on their design at the IEEE International Conference on Robotics and Automation this spring.

ieee.org

Dassault’s CATIA Announces “Creativity in 3D” Contest

Dassault Systèmes CATIA announces a creativity contest for confirmed and amateur designers, Creativty in 3D. Like clay modelers or sculptors, designers can use 3D software for live, intuitive design.

The contest opened Monday March 22. To qualify to win, candidates must submit entries on the 3D Perspectives blog no later than Friday May 7. The entries will be judged by a Dassault Systemes Jury board including DS Design Studio, and the winners will be announced on Wednesday May 19.

To learn more about the contest, see samples of 3D creative design, and apply, please visit: http://perspectives.3ds.com/2010/03/22/creativity-in-3d-contest/

Dassault Systèmes
www.3ds.com

Motion and Software

Rockwell Automation recently had it’s Automation Fair during which a number of new product announcement were made.  The company has announced a collaboration with Dassault Software Systems to create a suite of tools that deal with various applications of industrial automation and manufacturing on the plant floor.  Of particular interest to the mechatronics world is coordination between Solidworks modeling software and Rockwell’s Motion Analyzer.  In addition, Rockwell has made an important ease-of-use connection between the Motion Analyzer which has traditionally been used for sizing motors, and the control system software.

As an experienced user of early version of the Motion Analyzer, I used the software as a tool to analyze tradeoffs between time, torque and inertia to optimize customer machinery and processes in motion control applications.  Good motion control starts with good mechanical design, and there are so many variables and tradeoffs, that it’s often difficult to navigate your way to the best solution.  A good motion analysis tool automates the process so that you can examine an axis requirement and explore several options for how the axis can be optimized.

The results of the Motion Analyzer can be directly integrated into the PLC editor RSLogix.  This is usually an area where there is a major duplication of effort, since everything that you have to program in the control system is data that you have worked with in the Motion Analyzer.  So kudos to the Rockwell team for getting this feature added to the RSLogix suite.

The Motion Analyzer uses information about the Rockwell Automation motors and amplifiers to match inertias to loads and duty cycle requirements to the thermal capability of the equipment.  This is an often overlooked subltety of the equipment, but at the end of the day, it’s all about the amount of heat you can get rid of.  And the duty cycle contains all the critical information about how much energy you need, when you need it, and how long you have to dissipate it.  In addition, I have found that everyone’s idea of thermal modeling is different.  So it pays to do the simulation work at the front end of the design.

But, we always used to joke that we were doing solid modeling anyway.  Everything was a cylindrical object of a certain diameter, length, material density, etc.  So it stands to reason that integration with a 3D modeling system would make sense.  After all, a little step up in capability could lead to a lot better design work from the start. And the ability to link mechanical design at the earliest part of the design cycle, directly to the output at the motor and control system, makes for better outcomes every time.

Digital Prototyping in Mechatronic Design

By Keith Perrin
AUTODESK

Today’s manufacturers are using a mechatronics-based approach to integrate the electronic, mechanical, and software components of their increasingly complex products. Digital prototyping allows disparate engineering teams to work from a single digital model, saving time and reducing errors throughout the design process. The Autodesk solution for digital prototyping enables manufacturers to achieve the full benefits of mechatronics product development.

The need for a new approach
Today’s manufacturers face unrelenting pressure to continuously develop innovative new products. According to a survey of CEOs, two-thirds of executives believe that innovation is vital to the future of their companies. Their concern is understandable; according to one estimate, the products that generate nearly 70% of revenues today will be obsolete by 2010.

In response to this call for innovation, manufacturers have accelerated their adoption of electronics. Research shows that 92 percent of manufacturers now incorporate electronic elements into their products.

The automotive industry provides a prime example. While the proportion of a car’s cost that can be attributed to electronic systems has increased by an average of 8.3% per year over the past eight years, the proportion attributed to mechanical systems has decreased by an average of 3.2%. These trends are broadly consistent across all industries.

As manufacturers respond to the demands of the market, they must deal with the added complexities of synchronizing mechanical, electronic, and software elements into one integrated system. In the process, they must effectively coordinate disparate engineering teams. A mechatronics-based approach can help.

Effective mechatronics product development demands a focus on three key engineering activities:
• Multi-Disciplinary Design and Engineering. Mechatronics refers to the integration of control systems, electrical systems, and mechanical systems. A mechatronics system is not just a marriage of electrical and mechanical systems, and is more than just a control system. It is a complete integration of all of them. Top-performing manufacturers are 3.2 times more likely to allocate design requirements to systems.
• Managing Communication and Workflow. Integration of systems should be coupled with improvements in the coordination between the discipline-specific teams that are responsible for creating individual subsystems.

The often complex inter-relationships between individual sub-systems demand effective communication and clear ownership.7 Top-performing manufacturers are 2.8 times more likely to communicate change among their engineering disciplines.8
• Effective Early Validation. If manufacturers are going to develop cheaper, more reliable, and more flexible ystems, they must validate across the traditional boundaries of mechanical engineering, electrical engineering, electronics, and control engineering at the earliest stages of the design process. Top-performing manufacturers are 7.3 times more likely to digitally validate system behavior.

The mechatronics advantage
Manufacturers that harness the best practices of mechatronics can achieve significant benefits. Best-inclass manufacturers are more able to reach their targets for development costs, product revenue, and product quality, and to hit their product launch dates. Such manufacturers can also:
•  Add more features and functions.
•  Reduce the size, weight, and cost of their products.
•  Improve their overall efficiency.
• Leverage adaptive control and diagnostics to improve reliability and reduce maintenance costs.
•  Customize or upgrade products by reprogramming embedded firmware.

In addition, a mechatronics-based approach mitigates risk and solves common design challenges such as the slow, serial machine design process; poor communication between machine designers and customers; and risky physical machine testing.

Challenges of adopting a mechatronics approach
As manufacturers focus on improving their mechatronics product development processes, they often face significant challenges:

Finding design conflicts across disciplines depends largely on the knowledge base of the staff—and yet manufacturers list a lack of cross-functional knowledge as their leading challenge. Although hiring issues are partly to blame, manufacturers seldom have design tools that can integrate design data from all the elements that make up a product. As a result, their teams fail to understand the impact of design change across disciplines.

If manufacturers are going to achieve all the benefits of mechatronics product design, they clearly need technology solutions that enable their design disciplines to collaborate and communicate seamlessly, while also helping them identify system-level problems early, verify that all design requirements are met, and predict the behavior of the final product.

Key elements of a mechatronics solution
Ideally, a mechatronics solution should support the following best practices:
1. Multi-disciplinary design and engineering
2. Managing communication and workflow
3. Effective early validation

Multi-Disciplinary Design and Engineering
As the saying goes, “If you don’t know where you’re going, you’ll end up somewhere else.” In product development, knowing what you need is the first step to getting the final product right. Outlining product level requirements is necesssary to achieve the first step in outlining product performance. The ability to drive these key parameters into system and sub-system operational performance goals is often what sets leading manufacturers apart from their peers.

Many manufacturers assume that building a single, integrated design process across all disciplines is the best way to coordinate multi-disciplinary design and engineering so that all product requirements are met.

But statistics show that the extra effort spent on process engineering ultimately goes to waste. Instead, best-in-class manufacturers use separate design processes across disciplines in order to leverage the domain expertise of their designers. However, this requires that they be diligent in coordinating and synchronizing their engineering groups. This synchronization is key.

This approach is a best practice that should be adopted by other manufacturers seeking to improve their mechatronics design processes. From a practical perspective, this will require manufacturers to deploy focused engineering tools that allow individual disciplines to excel at their work, while providing the ability to share information easily. But it is not enough to be able to model these systems. System-level performance is usually a function of the disparate engineering and design needs of various sub-systems. Breaking down a system into its core constituents, therefore, demands some formality. As a result, it is essential to establish clear processes for effectively communicating changes, and to align collaboration and system engineering tools that can help make sure teams communicate changes effectively.

Managing communication and workflow
As manufacturers seek to coordinate and synchronize their separate engineering groups, there are many ways to bring information together. The average company often prefers to generate the bill of materials (BOM) from a customer database application. However, this method requires not only dedicated maintenance and support, but also manual synchronization of design information—making it complex and errorprone for a structure that contains thousands of parts.

Best-in-class manufacturers take advantage of discipline-specific structures for designing products. Rather than maintaining one large database across all groups, companies can use individual, discipline-specific databases that allow groups to manage their workgroup-level data and workflow at a local level.

But even the discipline-specific approach can create problems if manufacturers do not manage it correctly. Ultimately, manufacturers must strike a balance between providing the focus that engineering disciplines require and making certain that the data they create can be brought together easily.

Effective early validation
No one disputes that it is a good idea to resolve integration issues before committing money to tooling and manufacturing ramp-up. Leading manufacturers focus on resolving integration issues early in product development, and maintain this focus right up until verification and testing.

By focusing on validation, simulation, and verification earlier in the development process, manufacturers can avoid the costs and delays associated with resolving integrations later on. But to achieve these benefits, manufacturers must bring together a wide variety of design and engineering information for review. The goal is to synchronize the efforts of larger teams into single design reviews where all pertinent information is available at once. This is just one of the benefits of digital prototyping.

Driving mechatronics product development with digital prototyping
Rather than trying to integrate information from disconnected engineering systems, manufacturers can save time and money by enabling all their teams to work from the same digital model. Today, many best-in-class manufacturers are augmenting traditional physical prototyping by building digital prototypes. By tracking and comparing physical and digital prototype test results, these companies are gaining a deeper understanding of their products and the environments in which they operate—leading to greater overall product quality.

How digital prototyping enables best-in-class manufacturing
According to recent research, best-in-class manufacturers that use digital prototyping outpace averagemanufacturers by:
• Building 50 percent fewer physical prototypes.
• Getting products to market 58 days faster.
• Reducing prototyping costs by 48 percent.
• Freeing up time and resources for greater innovation.13

An action plan for mechatronics excellence
Although manufacturers have been talking about the benefits of digital prototyping for many years, the ability to build and test a true digital prototype has, until recently, been beyond the budgets of most manufacturing companies. In recent years, however, vendors have introduced increasingly practical solutions that are more attainable, scalable, and cost-effective than their predecessors.

Aberdeen Group has identified four key capabilities needed for best-in-class mechatronics product development:
• Implement processes to overcome the lack of cross-functional knowledge and promote better communication.
• Use simulation to identify system-level problems early in the design process.
• Manage design requirements throughout the entire design lifecycle.
• Accelerate the design of system controls with automated software tools and simulations.14

For all of these reasons, manufacturers should look for an integrated engineering suite that enables a digital prototyping workflow.

The Autodesk solution for digital prototyping
The Autodesk solution for Digital Prototyping helps mainstream manufacturers realize the full benefits of mechatronics by allowing them to quickly create and easily maintain a single, digital model. This model connects mechanical and electrical teams by bringing together design data from all phases of development for use across all disciplines. Because the digital model simulates the complete product, engineers can better visualize, optimize, and manage their design before producing a physical prototype.

As engineering teams work on the digital prototype, Autodesk’s data management tools integrate electrical and mechanical components into a single bill of materials (BOM). Using tightly integrated mechanical and electrical information, teams create more accurate 2D and 3D mechatronics designs in less time, enabling manufacturers to get to market faster.

The Tools, They are a Changing’

(regarding the title, just think Bob Dylan’s “The Times They are a Changin”)

Just as Computer Aided Design, CAD, has revolutionized the design process, it is growing in capability and impacting many other arenas of engineering. The first major extensions to CAD were integration of Finite Element Analysis, the ability to analyze loads on the parts being created.  And certainly, if the design software can model the complex aspects of loading, then animation of part motion can’t be a far reach.  And that’s the case today. Read more

Tradeoffs and Triangles

The activity of optimization involves trade off analysis.  The goal is to improve performance or cost effectiveness, or both if possible.  Nowadays, we have some really sophisticated software tools that allow us to simulate the behavior of complex systems. Computational fluid dynamics, magnetic field simulations, thermal imaging, finite element analysis are a few of the amazing technologies that can now be engaged on desktop computers to conduct sophisticated analysis of performance at the click of a mouse button.

Simulation work that used to require mainframe computing power is now generally available as an add on module to 3D engineering graphics products.  Most of the major 3D engineering design products include animation features that allow the user to build and move the parts in space exactly as they will do when built.  Read more

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